1. Field of the Invention
This invention relates generally to a multi-stage energy storage device, and more specifically to a multi-stage energy storage device having a multi-stage construction of energy storage units wherein energy is stored in a given stage of energy storage unit by means of the energy previously stored in the preceding stage of energy storage unit so as to obtain a relatively compact assembly incorporating a multiplicity of energy storage units to store large energy as a whole.
2. Description of the Prior Art
In a multi-stage energy storage unit, it is generally desired that each stage of energy storage units should almost uniformly store energy.
However, when storing energy in a given stage of energy storage unit by transmitting the energy previously stored in a preceding stage of energy storage unit to the said stage of energy storage unit, energy loss is usually caused in an energy transmitting mechanism intervening between the two stages of the multi-stage energy storage unit. When an energy transmitting mechanism employing two intermeshing gears of the same tooth number is used in such a case, energy may not be sufficiently transmitted from the preceding stage to the said stage due to the energy loss mentioned above. That is, whereas larger energy tends to be stored in the preceding stage, less energy in the said stage. This invention is intended to practically uniformly distribute energies to be stored to each stage of a multi-stage energy storage unit.